In manufacturing electronic devices, a plasma etching may be performed on a film of a workpiece. A plasma processing apparatus used in the plasma etching may be a capacitively coupled plasma processing apparatus. Generally, the capacitively coupled plasma processing apparatus includes a processing container, a placing table, an upper electrode, and a gas supply unit. The placing table includes a lower electrode, and is configured to support the workpiece within the processing container. The upper electrode is provided above the placing table. The gas supply unit is configured to supply a gas into the processing container. In the capacitively coupled plasma processing apparatus, a processing gas is supplied into the processing container from the gas supply unit, and the processing gas is excited by a high frequency electric field formed between the upper electrode and the lower electrode. Accordingly, plasma is generated. Then, the film of the workpiece is etched by active species of molecules and/or atoms constituting the processing gas.
The capacitively coupled plasma processing apparatus may include a plurality of electromagnets above the upper electrode. For example, the plurality of electromagnets are formed of a plurality of coils provided coaxially around a central axis passing through the center of the placing table in the vertical direction. Alternatively, the plurality of electromagnets are arranged along a plurality of concentric circles around the central axis and in the radial direction. Each electromagnet includes a coil provided around the axis extending in the vertical direction. The plurality of electromagnets are used to adjust a diametric distribution of the density of the plasma generated within the processing container, thereby adjusting a distribution of the etching rate in the diametric direction of the film of the workpiece. The etching of the film using such a plasma processing apparatus is described in, for example, Japanese Patent Laid-Open Publication No. 2014-158005.